This invention relates to high performance liquid chromatography, and more particularly, to chromatography columns adapted to be used in high performance liquid chromatography.
Columns or column blanks are utilized as part of high pressure liquid chromatography systems. The columns assist in the analyzation of mixtures and are of different diameters and lengths for different uses.
Traditional high performance liquid chromatography (HPLC) columns are rigid elongated tubes having threaded opposite interior ends to which threaded end fittings can be attached. These threaded end fittings have longitudinal passageways extending through their lengths and are adapted to receive fluid carrying tubes which transport the liquid mixture to be analyzed to and from the column. Alternatively female threaded couplers are secured around the column blank at opposite ends to receive the end fittings. Ferrules are mounted on the column ends to seal the column to the end fittings. These traditional commercial HPLC columns are not suitable because the end fittings and/or threads and/or ferrules occupy a space of several centimeters on the column blank and thus limit how short the column can be. Commercial columns are available generally in the range of 5-30 centimeters in length. Needs have arisen for columns of only a few millimeters in length and therefore these traditional columns are not able to satisfy this need.
Additionally, traditional HPLC columns are subject to damage because of the constant coupling and uncoupling of the end fittings and therefore are subject to leakage around the ferrules. Because certain instances require columns of varying inside diameter, not only are a variety of different columns needed but also the end fittings have to be changed to matingly seal with the column ends.
U.S. Pat. No. 4,280,905 utilizes a column which is encased by an outer sleeve which has threaded outside surfaces at opposite ends. End caps having threaded interior bores are then threaded down upon the opposite ends of the sleeve and compress seals against the ends of the column. This device also has a sealing means which seals the sleeve from the outside in order that pressure can be applied between the inner column and the outer sleeve. Although this design eliminates the problems associated with having a threaded column, it does not eliminate the problem of limiting how short the column can be because the outer screw caps tighten over the sleeve and therefore restrict how short the sleeve can be which therefore limits how short the column can be while maintaining a sealing relationship.
It is therefore an object of this invention to provide a column for high performance liquid chromatography which improves upon the deficiencies in the prior art.
Another object of this invention is to provide a column for high performance liquid chromatography which may be as short as a few millimeters in length.
Another object of this invention is to provide a column for high performance liquid chromatography which is not limited in how short it can be by the sleeve or end fittings.
A further object of this invention is to provide a column for high performance liquid chromatography which eliminates ferrules in the column.
A further object of this invention is to provide a column for high performance liquid chromatography which allows columns of varying inside diameters to be used with the same end fittings and sleeve.
Another object of this invention is to provide a column for high performance liquid chromatography which allows some variation in length of column utilizing the same fittings and sleeve.
Another object of this invention is to provide a column for high performance liquid chromatography which allows column blanks without threads or any other permanently affixed fittings to be used.
Another object of this invention is to provide a column for high performance liquid chromatography which allows the use of columns of substantially varying lengths while only requiring the use of different sleeves but utilizing the same end fittings.
A further object of this invention is to provide a column for high performance liquid chromatography which is not susceptible to damage or deformation of the inside of the column.
Another object of this invention is to provide a column for high performance liquid chromatography which improves upon the prior art substantially reducing the risk of leaks.
A further object of this invention is to provide a column for high performance liquid chromatography which can withstand high pressures without leaking.
Another object of this invention is to provide a column for high performance liquid chromatography wherein the parts most subject to damage or wear are cheaply and easily replaceable.
A further object of this invention is to provide a column for high performance liquid chromatography which is economical, efficient and durable.
Additional objects, features and advantages of the invention will become apparent with reference to the accompanying specification and drawings.